Meeting Abstracts

The SCEC collaboration emphasizes the connections between information gathering by sensor networks, fieldwork, and laboratory experiments; knowledge formulation through physics-based, system-level modeling; improved understanding of seismic hazard; and actions to reduce earthquake risk and promote resilience. Use the form below to search and view all poster and invited talk abstracts submitted to this meeting.

Results 251-300 of 355

SCEC ID	Category	Title and Authors	SCEC Award
Poster 294	GMSV	Surface topography effects in three-dimensional physics-based deterministic ground motion simulations in southern California Andrea Riaño, Doriam Restrepo, Ricardo Taborda, Jacobo Bielak Topographic features are known to contribute to ground motion amplification, especially at mountain ridges and edges. These amplifications occur due to the constructive interference between incoming motion with wavelengths comparable to the physical... more	16093
Talk 9/12 10:30	Geology	Open Intervals, Clusters and Supercycles: 1100 years of Moment Release in the Southern San Andreas Fault System: Are we Ready for the Century of Earthquakes? Thomas Rockwell Compilation of paleoseismic data from several dozen trench sites in the southern San Andreas fault system, along with geomorphic observations of displacement in recent earthquakes, allows for sequencing of the past 1100 years of large earthquakes... more	14049, 16114
Poster 148	Geodesy	Strain accumulation on faults beneath Los Angeles: a geodesy-based picture accounting for the effects of sedimentary basins and anthropogenic surface deformation Chris Rollins, Donald Argus, Walter Landry, Sylvain Barbot, Jean-Philippe Avouac The Los Angeles region is contracting at ~8 mm/yr in the N 5° E direction due to the misalignment of the Mojave section of the San Andreas Fault with the direction of relative Pacific-North American plate motion. This contraction is accommodated by... more
Poster 218	Seismology	Complex active faults and seismicity rates in the trifurcation area of the San Jacinto fault zone illuminated by aftershocks of the 2016 Mw 5.2 Borrego Springs earthquake Zachary Ross, Egill Hauksson, Yehuda Ben-Zion We summarize spatial properties and rates of early aftershocks of the Mw 5.2, June 2016, Borrego Springs earthquake and background seismicity in the trifurcation area of the San Jacinto Fault Zone. In this area, the fault zone splits into three... more
Poster 267	GMP	High-Frequency Nonlinear Simulations of Southern San Andreas Earthquake Scenarios Daniel Roten, Kim Olsen, Steven Day, Yifeng Cui The Southern San Andreas fault (SAF) is particularly likely to host a large earthquake in southern California, with a 19% chance of producing at least one M 6.7 earthquake during the next 30 years (UCERF3). Large-scale computational efforts to... more	16238, 16264
Poster 181	Seismology	Effects of regulation on induced seismicity in southern Kansas Justin Rubinstein, William Ellsworth, Sara Dougherty The appearance of seismicity concurrent with the expansion of oil and gas activities in southern Kansas since September 2012 suggests that industrial operations are inducing earthquakes there. Much of the seismicity can be related to high-rate... more
Poster 245	Seismology	An Investigation into the Eastern Extent of the Garlock Fault using Ground-based Magnetics and Seismotectonic Analysis Brad Ruddy, Jascha Polet The character of the Garlock fault has been a topic of contention among geologists since its discovery in 1910. The 250 km long Garlock fault strikes roughly east-west and its current surface expression is located between the San Andreas fault and... more
Poster 319	Simulators	Fakequakes: Earthquake Rupture Scenarios for California and Cascadia Christine Ruhl, Diego Melgar, Ronni Grapenthin, Mario Aranha, Richard Allen Limited geodetic observations of earthquakes greater than M6 make it difficult to test and improve GPS-based earthquake early warning systems, such as G-larmS. Scenario ruptures and ground motion simulations are therefore useful for studying... more
Poster 175	Seismology	Reducing Uncertainty in Ground Motion Prediction Equations by Understanding Path Effects Valerie Sahakian, Annemarie Baltay, Tom Hanks The differences between recorded ground motions and median predictions made by Ground Motion Prediction Equations (GMPEs) can be widely scattered, leading to large model standard deviations which can result in large ground motion amplitudes at low... more
Poster 295	GMSV	Topography effects in the near field for a dislocation point source: A comparison of the FEM-HERCULES code and the 3D IBEM Edilson Salazar Monroy, Leonardo Ramirez-Guzman, Marcial Contreras-Zazueta, Francisco Sanchez-Sesma We analyze a staircase and slope-dependant meshing strategy for modeling topographical features using the HERCULES finite element toolchain (Tu et al., 2006). We compare the Finite Element solution against the Integral Boundary Element Results using... more
Poster 130	SoSAFE	Investigating the age and origin of small offsets at Van Matre Ranch along the San Andreas Fault in the Carrizo Plain, California James Salisbury, Ramon Arrowsmith, Thomas Rockwell, Sinan Akciz, Nathan Brown, Lisa Grant Ludwig Small displacement fault-offset features (<10’s of m) are rarely dated, making it challenging to attribute slip to dated earthquakes. We investigated the ages of subtle fluvial depressions previously interpreted as beheaded channels representing... more	15139, 16201
Poster 141	Geodesy	The SCEC Community Geodetic Model V1: Horizontal Velocity Grid David Sandwell, Yuehua Zeng, Zheng-Kang Shen, Brendan Crowell, Jessica Murray, Robert McCaffrey, Xiaohua Xu The SCEC community is constructing and updating a suite of models for the Southern California region to facilitate cross-disciplinary research (CFM, CVM, CGM, CSM, and CRM). Here we are concerned with the development of the Community Geodetic Model... more	16072
Poster 293	GMSV	Kinematic source generation based on fractal fault geometries William Savran, Kim Olsen Simulating seismic wave propagation at frequencies of engineering interest (~10 Hz) requires a source description with extraordinary complexity, such as produced by geometrically rough faults. Although spontaneous ruptures on geometrically rough-... more	16117
Poster 121	SoSAFE	Comparison of the rupture history of the southern San Andreas fault with empirical data on fault displacement and rupture length Katherine Scharer Offset geomorphic features provide estimates of slip used to derive paleoearthquake moment magnitude based on empirical relationships from historic ruptures (e.g., Wells and Coppersmith, 1994; Wesnousky, 2008). Obtaining these measurements is... more
Poster 183	Seismology	The Origin of High-angle Dip-slip Earthquakes at Geothermal Fields in California Martin Schoenball, Patricia Martínez-Garzón, Andrew Barbour, Grzegorz Kwiatek We examine the source mechanisms of earthquakes occurring in three California geothermal fields: The Geysers, Salton Sea, and Coso. We find source mechanisms ranging from strike slip faulting, consistent with the tectonic settings, to dip slip with... more
Poster 313	CSEP	Regional evolution of network detection completeness in Japan Danijel Schorlemmer, Naoshi Hirata, Yuzo Ishigaki, Kazuyoshi Nanjo, Hiroshi Tsuruoka, Thomas Beutin, Fabian Euchner An important characteristic of any seismic network is its detection completeness, which should be considered a function of space and time. Many researchers rely on robust estimates of detection completeness, especially when investigating statistical... more
Poster 023	SDOT	Fault-parallel shear fabric in the ductile crust of Southern California imaged using receiver functions Vera Schulte-Pelkum, Karl Mueller We present results on deep crustal deformation fabric from a new receiver function method. The method uses the azimuthal variation of P-to-S converted arrivals on the radial and transverse component of receiver functions. Dipping isotropic velocity... more
Poster 324	CEO	Challenges and Opportunities for Communicating about Seismic Hazard Timothy Sellnow, Emina Herovic, Deanna Sellnow The complexity of seismic hazard information poses communication challenges for scientists charged with publicly communicating this information. Scientists must translate complex information for nonscientists who, in turn, make risk-based decisions... more
Poster 244	Seismology	Using a fast similarity search algorithm to identify repeating earthquake sequences Nader Shakibay Senobari, Gareth Funning Repeating earthquakes (REs) are the regular or semi-regular failures of the same patch on a fault, producing near-identical waveforms at a given station. Sequences of REs are commonly interpreted as slip on small locked patches surrounded by large... more
Poster 302	EFP	Precursory Swarm and Earthquake Forecasting in Indo-Nepal Himalaya Prof Daya SHANKER, Harihar Paudyal We investigate seismicity data from 1963-2006 in the light of three medium size earthquakes of 1980 (mb 6.1), 1984 (mb 5.6) and 1999 (mb 6.6) occurred in the Western Nepal and its adjoining Indian region which were preceded by well defined patterns... more
Poster 089	Geology	Preliminary results on Late Quaternary slip rate of the central Haiyuan Fault constrained by terrestrial in situ cosmogenic nuclides dating, UAV and LiDAR surveys Yanxiu Shao, Jing Liu, Michael Oskin, Jerome Van der Woerd, Jinyu Zhang, Peng Wang, Pengtao Wang, Wang Wang, Wenqian Yao Kinematic parameters of active faults are essential for understanding active tectonics, and evaluation of regional tectonic and crustal deformation models. Many study focus on large active faults and acquisition of their slip rates of multiple time... more
Poster 020	SDOT	Coulomb stress evolution over the past 200 years and seismic hazard along the Xianshuihe fault zone of Sichuan, China Zhigang Shao, Jing Xu, Hongsheng Ma, Langping Zhang This study focuses on the M ≥ 6.7 earthquakes that have occurred since 1816 on the Xianshuihe fault zone in southwest China. The interseismic Coulomb stress accumulation and the Coulomb stress changes caused by coseismic dislocation and postseismic... more
Poster 120	SoSAFE	High-resolution imaging of the San Andreas Fault around San Gorgonio Pass using fault zone head waves and double-difference tomography, with implications for large earthquake ruptures Pieter-Ewald Share, Yehuda Ben-Zion, Clifford Thurber, Haijiang Zhang, Hao Guo We attempt to clarify the seismic velocity structure within and around the complex San Gorgonio Pass (SGP) “structural knot” of the San Andreas Fault (SAF) using fault zone headwaves (FZHW) and a new double-difference tomography code incorporating... more
Poster 231	Seismology	Exploring the suitability of the Quake-Catcher Network in the USGS ShakeMap: Case studies from aftershocks of the 2010-2011 Darfield and Christchurch, New Zealand earthquakes Liam Shaughnessy, Danielle Sumy, Elizabeth Cochran, Corrie Neighbors, Robert-Michael de Groot Following the September 3, 2010, MW 7.1 Darfield, New Zealand earthquake, the Quake-Catcher Network (QCN; quakecatcher.net) team rapidly deployed 192 low-cost seismic sensors around Christchurch. These CodeMercenaries JoyWarrior JWF14F8 14-bit three... more
Poster 193	Seismology	Precise relative stress drops Bruce Shaw, William Ellsworth, Nana Yoshimitsu, Yihe Huang, Gregory Beroza Earthquake stress drops are generally observed to be independent of seismic moment but vary by three orders of magnitude or more for any moment value. If correct, this predicts far greater variability in high-frequency ground motions than is... more	16157, 15070
Poster 222	Seismology	Testing and Reconciling Stress Drop and Attenuation Models in Southern California Peter Shearer, Rachel Abercrombie, Daniel Trugman Earthquake stress drop is a fundamental source parameter, implicit in many SCEC science goals. It is relatively easy to estimate from seismic data, but hard to measure reliably and well. The large uncertainties and scatter in results affect strong... more	16020
Poster 217	Seismology	A new strategy for earthquake focal mechanisms using waveform-correlation-derived relative polarities and cluster analysis: Application to a fluid-driven earthquake swarm David Shelly, Jeanne Hardebeck, William Ellsworth, David Hill In microseismicity analyses, reliable focal mechanisms can typically be obtained for only a small subset of located events. We address this limitation here, presenting a framework for determining robust focal mechanisms for large populations of... more
Poster 274	GMP	Green’s functions retrieved by Multi-Component C3 for Ground Motion Prediction Yixiao Sheng, Gregory Beroza, Marine Denolle We follow the Virtual Earthquake Approach, proposed by Denolle et al (2013), to predict strong ground motion, based on the surface response determined from the ambient seismic field. Instead of just using cross-correlation (C1), we use C3, cross-... more
Poster 339	CME	Inferring Southern California Crustal Viscosity Structure from the SCEC Community Velocity Model William Shinevar, Mark Behn, Greg Hirth, Oliver Jagoutz In this study we constrain the viscosity of the lower crust through a joint analysis of the role of rock composition on seismic P-wave (Vp) , S-wave (Vs) velocities and rheology. Previous research has demonstrated robust relationships between... more	16106
Poster 163	Geodesy	Surface uplift and time-dependent seismic hazard due to fluid-injection: Cast studies from texas Manoochehr Shirzaei Increasing seismicity in the central USA since 2009 coincides in space and time with wastewater injection. However, observations of the surface deformation and physical models to constrain the extent to which fluid migrates and to unequivocally link... more
Talk 9/11 18:00	Geology	Earthquakes on Compressional Inversion Structures - Problems in Mechanics and in Hazard Assessment Richard Sibson The dip-distribution of near-pure reverse-slip ruptures includes a dominant ‘Andersonian’ cluster (dips of 30±5°) flanked by groups of low-angle thrusts (dips of 10±5°), and moderate-steep reverse faults (dips of 50±5°). These last are attributable... more
Poster 002	GMP	The SCEC Broadband Platform: Open-Source Software for Strong Ground Motion Simulation and Validation Fabio Silva, Christine Goulet, Philip Maechling, Scott Callaghan, Thomas Jordan The Southern California Earthquake Center (SCEC) Broadband Platform (BBP) is a carefully integrated collection of open-source scientific software programs that can simulate broadband (0-100 Hz) ground motions for earthquakes at regional scales. The... more
Poster 054	FARM	Natural polish in granitic rocks Shalev Siman-Tov, Emily Brodsky, Greg Stock Fault mirrors are highly smooth and reflective rock surfaces that are found in many shear zones around the world. Recent studies suggest that fault mirrors are formed during high velocity slip on faults and therefore may serve as an indicator for... more
Poster 083	Geology	Marine terraces, isostasy, earthquakes, and uplift rates Alexander Simms, Helene Rouby, Kurt Lambeck, Angela Roman Marine terraces line the southern California coast and have been used for decades to constrain rates of tectonic uplift. However, despite years of study two fundamental questions remain concerning their relationship to tectonic uplift. First, how... more
Poster 071	FARM	Dehydration-Induced Porosity Waves and Episodic Tremor and Slip Robert Skarbek, Alan Rempel Episodic tremor and slip (ETS) at plate interfaces takes place where there is abundant evidence for elevated, near-lithostatic pore pressures. In subduction zones and on the San Andreas fault, tectonic tremor occurs at depths where there is... more
Poster 189	Seismology	Proximity of Precambrian basement affects the likelihood of induced seismicity in the Appalachian, Illinois, and Williston basins Rob Skoumal, Michael Brudzinski, Brian Currie While most of the induced seismicity observed in the Central and Eastern U.S. has occurred in sedimentary basins that have experienced overall increases in oil and gas development (e.g., the Anadarko and Ft. Worth basins), other basins with similar... more
Poster 279	GMP	Frictional rheology for nonlinear attenuation: Implications for paleoseismology and strong S-waves Norman Sleep Strong Love waves and near-field velocity pulses impinge on sedimentary basins and hard rocks in California. Rock damage from past shaking provides paleoseismological evidence as well as evidence that frictional failure caused the damage. The... more	16001
Poster 258	Seismology	Magnitude and Peak Amplitude Relationship for Microseismicity Induced by Hydraulic Fracture Experiment Trevor Smith, Adam Arce, Chen Ji Waveform cross-correlation technique is widely used to improve the detection of small magnitude events induced by hydraulic fracturing. However, when events are detected, assigning a reliable magnitude is a challenging task, especially considering... more
Poster 010	SDOT	4D stress evolution models of the San Andreas Fault System using improved geodetic and paleoseismic constraints Bridget Smith-Konter, Karen Luttrell, Xiaopeng Tong, David Sandwell Major earthquakes of the San Andreas Fault System (SAFS) are thought to occur when accumulated fault stress in the upper locked portion of the crust exceeds some threshold value. 4D simulations of stress evolution provide rare insight into... more	16117
Poster 236	Seismology	Stochastic Representations of Seismic Anisotropy: Locally Isotropic Transversely Isotropic Media Xin Song, Thomas Jordan A self-consistent theory for the effective elastic parameters of stochastic media with small-scale 3D heterogeneities has been developed using a 2nd-order Born approximation to the scattered wavefield [Jordan,2015]. Our model assumes the medium can... more
Poster 007	USR	Displacement direction and 3D geometry for the south-directed North Channel – Pitas Point fault system and north-directed ramps, decollements, and other faults beneath Santa Barbara Channel. Christopher Sorlien, Craig Nicholson, Richard Behl, Marc Kamerling We use abundant seismic reflection data to interpret 3D fault geometry in the upper 5 to 8 km beneath Santa Barbara Channel and use dated and correlated seismic stratigraphy to study 3D fold geometry and its changes through Quaternary time. A set... more	15098
Poster 073	FARM	Modern earthquake ruptures on contrasting fault systems in the Laguna Salada region of northwestern Mexico. Ronald Spelz, John Fletcher, Thomas Rockwell, Alejandro Hinojosa, Michael Oskin, Lewis Owen, Jaziel Cambron, Víctor Villaverde, Laura Vallin, Abel Gutierrez, Keene Karlsson The Laguna Salada region of northwestern Mexico is located near the axis of the Pacific-North American plate margin and hosts a wide variety of active faults that accommodate the three dimensional strain of transtensional shearing. Individual fault... more	16190
Poster 186	Seismology	Body wave phases from higher order cross-correlation Zack Spica, Gregory Beroza Recent studies in ambient field seismology showed that body wave phases (direct and reflected) can be extracted from ambient-field cross-correlations. The latter offers the possibility to sample Earth’s deep reflector (i.e. the outer core) in remote... more
Poster 098	Geology	Reevaluation of high slip rates on the Eglington Fault Las Vegas, NV utilizing new chronostratigraphic and geologic evidence Kathleen Springer, Jeffrey Pigati The Eglington fault is a northeast striking monoclinal landform that offsets middle-late Pleistocene groundwater discharge deposits in the Las Vegas Valley by ~14 m vertically. Most of the exposure of the fault has been lost to extensive... more
Poster 058	FARM	Estimates of fault tractions in the San Gorgonio Pass region consider fault interaction Aviel Stern, Michele Cooke, Jennifer Beyer, Jennifer Tarnowski, David Oglesby, Roby Douilly In order to estimate absolute tractions along the southern San Andreas fault, we simulate the regional deformation using three-dimensional quasi-static mechanical models. These models simulate the stressing rates both over multiple earthquake... more
Poster 078	FARM	Post-seismic ductile flow beneath the brittle-plastic transition: constraints on rheology from microstructural and electron backscatter diffraction (EBSD) analyses of mylonitized pseudotachylite, South Mountains metamorphic core complex, Arizona Craig Stewart, Elena Miranda Post-seismic ductile flow promotes the upward rebound of the brittle-plastic transition (BPT) after an earthquake, but it is difficult to determine the rheologic controls on post-seismic flow due to compositional and structural heterogeneities in... more
Poster 227	Seismology	Using Waveform Modeling to Determine the Depth of the Deepest Earthquakes on and Near the Newport-Inglewood Fault Zone in the Los Angeles Basin Chloe Sutkowski, Jascha Polet The depth extent of many faults in the Los Angeles Basin is still poorly determined. It has been suggested that many are part of shallow decollement systems. However, Boles et al. (2015) conclude that a strong mantle helium signal along the Newport-... more
Poster 136	Geodesy	Fault creep observed on the Maacama and Rodgers Creek faults, northern California using PS-InSAR Jerlyn Swiatlowski, Gareth Funning Fault creep north of the San Francisco Bay Area has been observed in a few discrete locations, along the Maacama and Rodgers Creek faults, but the distribution of creep along these faults are not mapped in detail. This is due to a high degree of... more
Poster 132	Geodesy	Interpreting Oligocene Paleogeography in Southern California Using a Provenance Analysis of the Sespe Formation Carl Swindle, Parker Clarke The Sespe Formation is a lithified fluvial system that was deposited during the Oligocene. Previous geological investigations aimed at identifying the origins of the Sespe Formation have arrived at conflicting conclusions. This project assists in... more
Poster 272	GMP	Verification and Validation of High-Frequency (fmax = 5 Hz) Ground Motion Simulations of the 2014 M 5.1 La Habra, California, earthquake Ricardo Taborda, Kim Olsen, Robert Graves, Fabio Silva, Naeem Khoshnevis, William Savran, Daniel Roten, Zheqiang Shi, Christine Goulet, Jacobo Bielak, Philip Maechling, Yifeng Cui, Thomas Jordan The Southern California Earthquake Center (SCEC) High-F project seeks to advance physics-based, deterministic earthquake simulation with the long-term objective of improving ground motion prediction and seismic hazard models. An important aspect of... more

The Southern California Earthquake Center is committed to providing a safe, productive, and welcoming environment for all participants. We take pride in fostering a diverse and inclusive SCEC community, and therefore expect all participants to abide by the SCEC Activities Code of Conduct.

Category:
Author:
Title:
Abstract:
Format:
Only show abstracts with PDFs

Meeting Abstracts

IMPORTANT DATES

For Researchers

For The Media